Saturday, 6 October 2012

8.1.Fluid is a substance that
(a)cannot be subjected to shear forces
(b)always expands until it fills any con-tainer
(c)has the same shear stress.at a point regardless of its motion
(d)cannot remain at rest under action of any shear force
(e)flows.

8.22.The normal stress in a fluid will be constant in all directions at a point only if
(a)it is incompressible
(b)it has uniform viscosity
(c)it has zero viscosity
(d)it is frictionless
(e)it is at rest.
Ans: e

8.23.The pressure at a point in a fluid will not be same in all the directions when the fluid is
(a) moving
(b) viscous
(c)viscous and static
(d)inviscous and moving
(e)viscous and moving.
Ans: e

8.36.The bulk modulus of elasticity
(a)has the dimensions of 1/pressure
(b)increases with pressure
(c)is large when fluid is more compres¬sible
(d)is independent of pressure and viscosity
(e)is directly proportional to flow.
Ans: b

8.37.A balloon lifting in air follows the following principle
(a)law of gravitation
(b)Archimedes principle
(c)principle of buoyancy
(d)all of the above
(e)continuity equation.
Ans: d

8.38.The value of the coefficient of compressibility for water at ordinary pressure and temperature in kg/cm is equal to
(a) 1000
(b) 2100
(c) 2700
(d) 10,000
(e) 21,000.
Ans: e

8.39.The increase of temperature results in
(a)increase in viscosity of gas
(b)increase in viscosity of liquid
(c)decrease in viscosity of gas
(d)decrease in viscosity of liquid
(e)(a) and (d) above.
Ans: d

8.41.Surface tension
(a)acts in the plane of the interface normal to any line in the surface
(b)is also known as capillarity
(c)is a function of the curvature of the interface
(d)decreases with fall in temperature
(e)has no units.
Ans: a

8.50.For manometer, a better liquid combination is one having
(a)higher surface tension
(b)lower surface tension
(c)surface tension is no criterion
(d)high density and viscosity
(e)low density and viscosity.
Ans: a

8.51.If mercury in a barometer is replaced by water, the height of 3.75 cm of mercury will be following cm of water
(a) 51 cm
(b) 50 cm
(c) 52 cm
(d) 52.2 cm
(e) 51.7 cm.
Ans: a

8.52.Choose the wrong statement.
Alcohol is used in manometer, because
(a)its vapour pressure is low
(b)it provides suitable meniscus for the in-clined tube
(c)its density is less
(d)it provides longer length for a given pressure difference
(e)it provides accurate readings.
Ans: a

53.Increase in pressure at the outer edge of a drum of radius R due to rotation at corad/sec, full of liquid of density p will be
(a) pco2/?2
(b) pco2/?2/2
(c)2pa2R2
(d) pa2R/2
(e) none of the above.
Ans: b

8.54.The property of fluid by virtue of which it offers resistance to shear is called
(a)surface tension
(b)adhesion
(c) cohesion
(d)viscosity
(e) all of the above.
Ans: d

8.55.Choose the wrong statement
(a)fluids are capable of flowing
(b)fluids conform to the shape of the con-taining vessels
(c)when in equilibrium, fluids cannot sus-tain tangential forces
(d)when in equilibrium, fluids can sustain shear forces
(e) fluids have some degree of compres-sibility and offer little resistance to form.
Ans: d

8.57.If w is the specific weight of liquid and k the depth of any point from the surface, then pressure intensity at that point will be
(a) h
(b) wh
(c) w/h
(d) h/w
(e) h/wh.
Ans: b

8.58.Choose the wrong statement
(a)Viscosity of a fluid is that property which determines the amount of its resistance to a shearing force
(b)Viscosity is due primarily to interaction between fluid molecules
(c)Viscosity of liquids decreases with in-crease in temperature
(d) Viscosity of liquids is appreciably af-fected by change in pressure
(e) Viscosity is expressed as poise, stoke, or saybolt seconds.
Ans: d

8.59. The units of kinematic viscosity are
(a)metres2 per sec
(b)kg sec/metre
(c)newton-sec per metre
(d) newton-sec per metre
(e) none of the above.
Ans: a

4.62. Which of the following is the unit of kinematic viscosity
(a) pascal
(b) poise
(c) stoke
(d) faraday
(e) none of the above.
Ans: c

$.63. A one dimensional flow is one which
(a)is uniform flow
(b)is steady uniform flow
(c)takes place in straight lines
(d)involves zero transverse component of flow
(e)takes place in one dimension.
Ans: d

8.69.Free surface of a liquid tends to contract to the smallest possible area due to force of
(a)surface tension
(b)viscosity
(c) friction
(d) cohesion
(e) adhesion.
Ans: a

8.70.A bucket of water is hanging from a spring balance. An iron piece is suspended into water without touching sides of bucket from another support. The spring balance reading will
(a) increase
(b) decrease
(c)remain same
(d)increase/decrease depending on depth of immersion
(e)unpredictable.
Ans: c

8.71.Falling drops of water become spheres due to the property of
(a) adhesion
(b) cohesion
(c)surface tension
(d)viscosity
(e) compressibility.
Ans: c

8.72.A liquid would wet the solid, if adhesion forces as compared to cohesion forces are
(a) less
(b) more
(c)equal
(d)less at low temperature and more at high temperature
(e)there is no such criterion.
Ans: b

8.73.If cohesion between molecules of a fluid is greater than adhesion between fluid and glass, then the free level of fluid in a dipped glass tube will be
(a)higher than the surface of liquid
(b)the same as the surface of liquid
(c)lower than the surface of liquid
(d)unpredictable
(e) none of the above.
Ans: c

8.74.The point in the immersed body through which the resultant pressure of the liquid may be taken to act is known as
(a) meta centre
(b) centre of pressure
(c)centre of buoyancy
(d)centre of gravity
(e)none of the above.
Ans: b

8.76.The resultant upward pressure of a fluid on a floating body is equal to the weight of the fluid displaced by the body. This definition is according to
(a)Buoyancy
(b)Equilibrium of a floating body
(c)Archimedes' principle
(d)Bernoulli's theorem
(e)Metacentric principle.
Ans: c

8.77.The resultant upward pressure of the fluid on an immersed body is called
(a)upthrust
(b) buoyancy
(c)centre of pressure
(d)all the above are correct
(e)none of above is correct.
Ans: b

8.78.The conditions for the stable equilibrium of a floating body are
(a)the meta-centre should lie above the centre of gravity
(b)the centre of buoyancy and the centre of gravity must lie on the same vertical line
(c)a righting couple should be formed
(d)all the above are correct
(e)none of the above is correct.
Ans: d

8.80.Metacentric height is given as the distance between
(a)the centre of gravity of the body andthe meta centre
(b)the centre of gravity of the body and the centre of buoyancy
(c)the centre of gravity of the body and the centre of pressure
(d)centre of buoyancy and metacentre
(e)none of the above.
Ans: a

8.81.The buoyancy depends on
(a)mass of liquid displaced
(b)viscosity of the liquid
(c)pressure of the liquid displaced
(d)depth of immersion
(e)none of the above.
Ans: a

8.82.The centre of gravity of the volume of the liquid displaced by an immersed body is called
(a)meta-centre
(b)centre of pressure
(c)centre of buoyancy
(d)centre of gravity
(e)none of the above.
Ans: c

8.83.A piece of metal of specific gravity 13.6 is placed in mercury of specific gravity 13.6, what fraction of it volume is under mercury?
(a)the metal piece will simply float over the mercury
(b)the metal piece will be immersed in mercury by half
(c)whole of the metal piece will be im-mersed with its top surface just at mer-cury level
(d)metal piece will sink to the bottom
(e)none of the above.
Ans: c

8.84.The angle of contact in case of a liquid depends upon
(a)the nature of the liquid and the solid
(b)the material which exists above the free surface of the liquid
(c)both of die above
(d)any one of the above
(e)none of die above.
Ans: c

3.85. Free surface of a liquid behaves like a sheet and tends to contract to smallest possible area due to the
(a)force of adhesion
(b)force of cohesion
(c)force of friction
(d)force of diffusion
(e)none of die above.
Ans: b

90. If the surface of liquid is convex, men
(a)cohesion pressure is negligible
(b)cohesion pressure is decreased
(c)cohesion pressure is increased
(d)there is no cohesion pressure
(e)none of the above.
Ans: c

91. To avoid vaporisation in the pipe line, the pipe line over the ridge is laid such that it is not more than
(a)2.4 m above the hydraulic gradient
(b)6.4 m above the hydraulic gradient
(c)10.0 m above the hydraulic gradient
(d)5.0 above the hydraulic gradient
(e)none of the above.
Ans: b

8.92.To avoid an interruption in the flow of a syphon, an air vessel is provided
(a) at the inlet
(b) at the outlet
(c)at the summit
(d)ay nay point between inlet and outlet
(e)none of the above.
Ans: c

8.93.The vapour pressure over the concave surface is
(a)less man the vapour pressure over the plane surface
(b)equal to the vapour pressure over the plane surface
(c)greater than the vapour pressure over the plane surface
(d)zero
(e) none of the above.
Ans: a

8.94.The peoperty by virtue of which a liquid opposes relative motion between its different layers is called
(a)surface tension
(b)co-efficient of viscosity
(c)viscosity
(d) osmosis
(e)cohesion.
Ans: c

8.95.The process of diffusion of one liquid into the other through a semi-permeable membrane is called
(a) viscosity
(b) osmosis
(c)surface tension
(d)cohesion
(e) diffusivity.
Ans: b

8.99.The rise or depression of liquid in a tube due to surface tension wim increase in size of tube will
(a)increase
(b)remain unaffected
(c)may increase or decrease depending on the characteristics of liquid
(d)decrease
(e)unpredictable.
Ans: d

8.100.Liquids transmit pressure equally in all the directions. This is according to
(a)Boyle's law
(b)Archimedes principle
(c)Pascal's law
(d) Newton's formula
(e)Chezy's equation.
Ans: c

8.101.Capillary action is due to the
(a) surface tension
(b) cohesion of the liquid
(c) adhesion of the liquid molecules and the molecules on the surface of a solid
(d) all of the above
(e) none of the above.
Ans: d

8.103.Newton's law of viscosity is a relationship between
(a)shear stress anctthejiate of angular dis¬tortion
(b)shear stress and viscosity
(c)shear stress, velocity and viscosity
(d)pressure, velocity and viscosity
(e)shear stress, pressure and rate of an-gular distortion.
Ans: a

8.104.The atmospheric pressure with rise in altitude decreases
(a)linearly
(b)first slowly and then steeply
(c)first steeply and then gradually
(d)unpredictable
(e)none of the above.
Ans: b

8.108.In an isothermal atmosphere, the pressure
(a)decreases linearly with elevation
(b)remains constant
(c)varies in the same way as the density
(d)increases exponentially with elevation
(e)unpredictable.
Ans: c

8.109.Mercury is often used in barometer because
(a) it is the best liquid
(b) the height of barometer will be less
(c)its vapour pressure is so low that it may be neglected
(d)both (b) and (c)
(e)it moves easily.
Ans: d

8.119.Dynamic viscosity of most of the liquids with rise in temperature
(a) increases
(b) decreases
(a) remains unaffected
(d)unpredictable
(e) none of the above.
Ans: b

8.120.Dynamic viscosity of most of the gases with rise in temperature
(a) increases
(b) decreases
(c) remains unaffected
(d) unpredictable
(e) none of the above.
Ans: a

8.121.A metal with specific gravity of o floating in a fluid of same specific gravity a will
(a) sink to bottom
(b)float over fluid
(c)partly immersed
(d)be fully immersed with top surface at fluid surface
(e)none of the above.
Ans: d

8.131.Working principle of dead weight pressure gauge tester is based on
(a)Pascal's law
(b)Dalton's law of partial pressure
(c)Newton's law of viscosity .
(d)Avogadro's hypothesis
(e)Second law of thermodynamic.
Ans: a

8.133.Centre of pressure compared to e.g. is
(a) above it
(b) below it.
(c)at same point
(d)above or below depending on area of body
(e)none of the above.
Ans: b

8.134.Metacentric height is the distance between the metacentre and
(a) water surface
(b) centre of pressure
(c)centre of gravity
(d)centre of buoyancy
(e)none of the above.
Ans: c

8.135.. The resultant upward pressure of the fluid on an immersed body due to its tendency to uplift the sub-merged body is called
(a) upthrust
(b) reaction
(c) buoyancy
(d) metacentre
(e) centre of pressure.
Ans: c

8.136.The centre of pressure of a surface subjected to fluid pressure is the point
(a)on the surface at which resultant pres-sure acts
(b)on the surface at which gravitational force acis
(c)at which all hydraulic forces meet
(d)similar to metacentre
(e)where pressure equivalent to hydraulic thrust will act.
Ans: a

8.137.Buoyant force is
(a)the resultant force acting on a floating body
(b)the resultant force on a body due to the fluid surrounding it
(c)equal to the volume of liquid dis-placed
(d)the force necessary to maintain equi-librium of a submerged body
(e)none of the above.
Ans: b

140. The line of action of the buoyant force acts through the
(a)centroid of the volume of fluid verti-cally above the body
(b)centre of the volume of floating body
(c)centre of gravity of any submerged body
(d)centriod of the displaced volume of fluid
(e)none of the above.
Ans: d

8.141. Centre of buoyancy is the
(a)centroid of the displaced volume of fluid
(b)centre of pressure of displaced volume
(c)e.g. of floating 'body
(d) does not exist
(e) none of the above.
Ans: a

8.142. A body floats in stable equilibrium
(a)when its meatcentric height is zero
(b)when the metancentre is above e.g.
(c)when its e.g. is below it's centre of buoyancy
(d)metacentre has nothing to do with position of e.g. for determining stability
(e) none of the above.
Ans: b

vl43. A piece weighing 3 kg in air was found to weigh 2.5 kg when submerged in water. Its specific gravity is
(a) 1
(b) 5
(c) 7
(d) 6
Ans: d

8.151.The total pressure force on a plane area is equal to the area multiplied by the intensity of pressure at the centriod, if
(a)the area is horizontal
(b)the area is vertical
(c)the area is inclined
(d)all of the above
(e) none of the above.
Ans: d

8.153.The df pth of the centre of pressure on a vertical rectangular gate 8 m wide and 6 m high, when the water surface coincides with the top of the gate, is
(a) 2.4 m
(b) 3.0 m
(c) 4.0 m
(d)"2.5 m
(e) 5.0 m.
Ans: b

8.154.If the atmospheric pressure on the surface of an oil tank (sp. gr. 0.8) is 0.2 kg/cm", the pressure at a depth of 50 m below the oil surface will be
(a)2 metres of water column
(b)3 metres of water column
(c)5 metres of water column
(d)6 metres of water Column
(e)7 metres of water column.
Ans: d

8.155.Metacentre is the point of intersection of
(a)vertical upward force through e.g. of body and centre line of body
(b)buoyant force and the centre line of body
(c)mid point between e.g. and centre of buoyancy
(d)all of the above
(e)none of the above.
Ans: b

8.156.Choose the wrong statement
(a)The horizontal component of the hydro-static force on any surface is equal to the normal force on the verti¬cal projection of the surface
(b)The horizontal component acts through the centre of pressure for the vertical projection
(c)The vertical component of the hydros-tatic force on any surface is equal to the weight of the volume of the liquid above the area
(d)he vertical component passes through the centre of pressure of the volume
(e)Centre of pressure acts at a greater depth than centre of gravity.
Ans: d

8.157.For a body floating in a liquid the normal pressure exerted by the liquid acts at
(a)bottom surface of the body
(b)e.g. of the body
(c)metacentre
(d)all points on the surface of the body
(e)all of the above.
Ans: d

8.158.Choose the wrong statement
(a) any weight, floating or immersed in a liquid, is acted upon by a buoyant force
(p) Buoyant force is equal to the weight of the liquid displaced
(c)The point through which buoyant force acts, is called the centre of buoyancy
(d)Centre of buoyancy is located above the centre of gravity of the displaced liquid v
(e)Relative density of liquids can be determined by means of the depth of flotation of hydrometer.
Ans: d

8.159.According to the principle of buoyancy a body totally or partially immersed in a fluid will be lifted up by a force equal to
(a) the weight of the body
(b)more than the weight of the body
(c)less than the weight of the body
(d)weight of the fluid displaced by the body
(e)weight of body plus the weight of the fluid displaced hy the body.
Ans: d

8.160.When a body floating in a liquid, is displaced slightly, it oscillates about
(a) e.g. of body
(b) centre of pressure
(c)centre of buoyancy
(d)metacentre
(e) liquid surface.
Ans: d

5.161.Buoyant force is
(a)resultant force acting on a floating body
(b)equal to the volume of liquid dis¬placed
(c)force necessary to keep a body in equi¬librium
(d)the resultant force on a body due to the fluid surrounding it
(e)none of the above.
Ans: d

8.l62. Ratio of inertia force to surface Jension is known as
(a)Mach number
(b)Froude number
(c)Reynold's number
(d)Weber's number
(e)none of the above.
Ans: d

165. A model of torpedo is tested in a towing tank at a velocity of 25 m/sec. The prototype is expected to attain a velocity
of 5 m/sec. What model scale has been used ?
(a) 1 : 5
(b) 1 : 2.5
(c) 1 :25
(d) 1:V5"
(e) 1 : 53/2
Ans: a

8.166.Ratio of inertia force to elastic force is known as
(a)Mach number
(b)Froude number
(c)Reynold's number
(d)Weber's number
(e)none of the above.
Ans: a

8.167.For a floating body to be in stable equilibrium, its metacentre should be
(a)below the centre of gravity
(b)below the centre of buoyancy
(c)above the centre of buoyancy
(d)between e.g. and centre of pressure
(e)above the centre of gravity.
Ans: e

8.168.For a floating body to be in equilibrium
(a)meta centre should be above e.g.
(b)centre of buoyancy and e.g. must lie on same vertical plane
(c)a righting couple should be formed
(d)all of the above
(e)none of the above.
Ans: d

8.170.Choose the wrong statement
(a)The centre of buoyancy is located at the centre of gravity of the displaced liquid
(b)For stability of a submerged body, the centre of gravity of body must lie directly below the centre of buoyancy
(c)If e.g. and centre of buoyancy coin¬cide, the submerged body must lie at neutral equilibrium for all positions
(d)For stability of floating cylinders or spheres, the e.g. of body must lie below the centre of buoyancy
(e)All floating bodies are stable.
Ans: e

8.171.Centre of pressure on an inclined plane is
(a) at the centroid
(b) above the centroid
(c)below the centroid
(d)at metacentre
(e)at centre of pressure.
Ans: c

8.172.An open vessel of water is accelerated up an inclined plane. The free water surface will
(a)be horizontal
(b)make an angle in direction of inclina¬tion of inclined plane
(c)make an angle in opposite direction to inclination of inclined plane
(d)any one of above is possible
(e)none of the above.
Ans: c

8.173.The line of action of the buoyant force acts through the centroid of the
(a)submerged body
(b)volume of the floating body
(c)volume of the fluid vertically above the body
(d)displaced volume of the fluid
(e)none of the above.
Ans: d

8.174.Resultant pressure of the liquid in the case of an immersed body acts through
(a)centre of gravity
(b)centre of pressure
(c)metacentre
(d) centre of buoyancy
(e) in between e.g. and centre of pressure.
Ans: b

8.175.The centre of gravity of the volume of the liquid displaced by an immersed body is called
(a)centre of gravity
(b)centre of pressure
(c)metacentre
(d)centre of buoyancy
(e)centroid.
Ans: d

8.177.The pressure in the air space above an oil (sp. gr. 0.8) surface in a tank is 0.1 kg/cm".
The pressure at 2.5 m below the oil surface will be
(a)2 metres of water column
(b)3 metres of water column
(c)3.5 metres of water column
(d)4 m of water column
(e)none of the above.
Ans: b

8.178.The time oscillation of a floating body with increase in metacentric height will be
(a)same
(b) higher
(c)lower
(d)lower/higher depending on weight of body
(e)unpredictable.
Ans: c

8.179.In an immersed body, centre of pressure is
(a) at the centre of gravity
(b)above the centre of gravity
(c)below be centre of gravity
(d)could be above or below e.g. depend¬ing on density of body and liquid
(e)unpredictable.
Ans: c

8.180.The normal stress is same in all directions at a point in a fluid
(a) only when the fluid is frictionless
(b)only when the fluid is incompressible and has zero viscosity
(c)when there is no motion of one fluid layer relative to an adjacent layer
(d) irrespective of the motion of one fluid layer relative to an adjacent layer
(e) in case of an ideal fluid.
Ans: c

8.184.For measuring flow by a venturimeter, if should be installed in
(a) vertical line
(b) horizontal line
(c)inclined line with flow downward
(d)inclined line with upward flow\
(e)in any direction and in any location.
Ans: e

8.188.Flow of water in a pipe about 3 metres in diameter can be measured by
(a) orifice plate
(b) venturi
(c) rotameter
(d) pitot tube
(e) nozzle
Ans: d

8.189.True one-dimensional flow occurs when
(a)the direction and magnitude of the veiocity at all points are identical
(b)the velocity of successive fluid par-ticles, at any point, is the same at suc-cessive periods of time
(c)the magnitude and direction of the velocity do not change from point to point in the fluid
(d)the fluid particles move in plane or parallel planes and the streamline pat-terns are identical in each plane
(e)velocity, depth, pressure etc. change from point to point in the fluid flow.
Ans: a

8.191.In the case of steady flow of a fluid, the acceleration of any fluid particle is
(a) constant
(b) variable
(c)zero
(d)zero under limiting conditions
(e)never zero.
Ans: c

8.193.Non uniform flow occurs when
(a)the direction and magnitude of the velocity at all points are identical
(b)the velocity of successive fluid par-ticles, at any point, is the same at suc-cessive periods of time
(c)the magnitude aricf direction of the velocity do not change from point to point in the fluid
(d)the fluid particles move in plane or parallel planes and the streamline pat-terns are identical in each plane
(e)velocity, depth, pressure, etc. change from point to point in the fluid flow.
Ans: e

8.197.Steady flow occurs when
(a)the direction and magnitude of the velocity at all points are identical
(b)the velocity of successive fluid par-ticles, at any point, is the same at suc-cessive periods of time
(c)the magnitude and direction of the velocity do not change from point to point in the fluid
(d)the fluid particles move in plane or parallel planes and the streamline pat-terns are identical in each plane
(e)velocity, depth, pressure, etc. change from point to point in the fluid flow.
Ans: b

8.199.The flow in which each liquid particle has a definite path and their paths do not cross each other is called
(a)one dimensional flow
(b)uniform flow
(c)steady flow
(d)turbulent flow
(e)streamline flow.
Ans: e

8.200.The flow in which conditions do not change with time at any point, is known as
(a)one dimensional flow
(b)uniform flow
(c)steady flow
(d)turbulent flow
(e)streamline flow.
Ans: c

8.201.The flow in which the velocity vector is identical in magnitude and direction at every point, for any given instant, is known as
(a)one dimensional flow
(b)uniform f^w
(c)steady flow
(d)turbulent flow
(e) streamline flow.
Ans: b

8.202.The flow in which the particles of a fluid attain such velocities that vary from point to point in magnitude and direction as well as from instant to instant, is known as
(a) one dimensional flow
(b) uniform flow
(c) steady flow
(d) turbulent flow
(e) streamline flow.
Ans: d

8.210.Flow occurring in a pipeline when a valve is being opened is
(a) steady
(b) unsteady
(c) laminar
(d) vortex
(e) rotational.
Ans: b

8.212.A streamline is defined as the line
(a) parallel to central axis flow
(b) parallel to outer surface of pipe
(c)of equal yelocity in a flow
(d)along which the pressure drop is uniform
(e)which occurs in all flows.
Ans: c

8.213.Two dimensional flow occurs when
(a)the direction and magnitude of the velocity at all points are identical
(b)the velocity of successive fluid par-ticles, at any point, is the same at suc-cessive periods of time
(c)the magnitude and direction of the velocity do not change from point to point in the fluid
(d)the fluid particles move in plane or parallel planes and the streamline pat-terns are identical in each plane
(e)velocity, depth, pressure, etc. change from point to point in the fluid flow.
Ans: d

8.226.Uniform flow occurs when
(a)the direction and magnitude of the velocity at all points are identical
(b)the velocity of successive fluid pai-ticles, at any point, is the same at suc¬cessive periods of time
(c)the magnitude and direction of the velocity do not change from point to point in the fluid
(d)the fluid particles move in plane or parallel planes and the streamline pat-terns are identical in each plsr.e
(e)velocity, depth, pressure, etc. change from point to point in the fluid flow.
Ans: c

8.228.Hydrometer is used to determine
(a)specific gravity of liquids
(b)specific gravity of solids
(c)specific gravity of gases
(d)relative humidity
(e)density.
Ans: a

8.229.The total energy of each particle at various places in the case of perfect incompres sible fluid flowing in continuous sream
(d) keeps on increasing
(b)keeps on decreasing
(c)remains constant
(d)may increase/decrease
(e)unpredictable.
Ans: c

8.230.According to Bernoulli's equation for steady ideal fluid flow
(a)principle of conservation of mass holds
(b)velocity and pressure are inversely proportional
(c)total energy is constant throughout
(d)the energy is constant along a stream-line but may vary across streamlines
(e)none of the above.
Ans: d

8.231.The equation of continuity holds good when the flow
(a)is steady
(b)is one dimensional
(c)velocity is uniform at all the cross sec-tions
(d)all of the above
(e)none of the above.
Ans: d

8.232.Mach number is significant in
(a)supersonics, as with projectiles and jet propulsion
(b)full immersion or completely enclosed flow, as with pipes, aircraft wings, nozzles etc.
(c)simultaneous motion through two fluids where there is a surface of dis-continuity, gravity force, and wave making effects, as with ship's hulls
(d)all of fhe above
(e)none of the above.
Ans: a

8.233.Froude number is significant in
(a)supersonics, as with projectile and jet propulsion
(b)full immersion or completely enclosed flow, as with pipes, aircraft wings, nozzles etc.
(c)simultaneous motion through two fluids where there is a surface of dis-continuity, gravity forces, and wave making effect, as with ship's hulls
(d)all of the above
(e)none of the above
Ans: c

8.235.Reynolds number is significant in
(a)supersonics, as with projectile and jet propulsion
(b)full immersion or completely enclosed flow, as with pipes, aircraft wings, nozzles etc.
(c)simultaneous motion through two fluids where there is a surface of dis-continuity, gravity forces, and wave making effect, as with ship's hulls
(d)all of the above
(e)none of the above.
Ans: b

8.236. The fluid forces considered in the Navier Stokes equation are
(a)gravity, pressure and viscous
(b)gravity, pressure and turbulent
(c)pressure, viscous and turbulent
(d)gravity, viscous and turbulent
(e)none of the above.
Ans: a

8.239.For pipes, laminar flow occurs when Roynolds number is
(a) less than 2000
(b) between 2000 and 4000
(c)more than 4000
(d)less than 4000
(e)none of the above.
Ans: a

8.240.In order that flow takes place between two points in a pipeline, the differential pressure between these points must be more than
(a)frictional force
(b)viscosity
(c)surface friction
(d)all of the above
(e)none of the above.
Ans: d

8.241.At the centre line of a pipe flowing under pressure where the velocity gradient is zero, the shear stress will be
(a) minimum
(b) maximum
(c) zero
(d) negative value
(e) could be any value.
Ans: e

8.242.The pressure in Pascals at a depth of 1 m below the free surface of a body of water will be equal to
(a) 1 Pa
(b) 98.1Pa
(c) 981 Pa
(d) 9810 Pa
(e) 98,100 Pa.
Ans: d

8.244.Two pipe systems can be said to be equivalent, when the following quantites are same
(a)friction loss and flow
(b)length and diameter
(c)flow and length
(d)friction factor and diameter
(e)velocity and diameter.
Ans: a

8.245.For pipes, turbulent flow occurs when Reynolds number is
(a) less than 2000
(b)between 2000 and 4000
(c). more than 4000
(d)less than 4000
(e)none of the above.
Ans: c

8.249.Cavitation will begin when
(a)the pressure at any location reaches an absolute pressure equal to the saturated vapour pressure of the liquid
(b)pressure becomes more than critical pressure
(c)flow is increased
(d)pressure is increased
(e)none of the above.
Ans: a

8.250.Principle of similitude forms the basis of
(a)comparing two identical equipments
(b)designing models so that the result can be converted to prototypes
(c)comparing similarity between design and actual equipment
(d)hydraulic designs
(e)performing acceptance tests.
Ans: b

8.251.For similarity, in addition to models being geometrically similar to prototype, the following in both cases should also be equal
(a)ratio of inertial force to force due to viscosity
(b)ratio of inertial force to force due to gravitation
(c)ratio of inertial force to force due to surface tension
(d)all the four ratios of inertial force to force due to viscosity, gravitation, sur-face tension, and elasticity
Ans: d